Trinamic TMCM-1180-CANopen Owner's manual

Trinamic
Brand
Trinamic
Model
TMCM-1180-CANopen
Type
Owner's manual

This manual is also suitable for

MECHATRONIC DRIVE WITH STEPPER MOTOR PANdrive
TRINAMIC Motion Control GmbH & Co. KG
Hamburg, Germany
www.trinamic.com
Hardware Version V1.1
HARDWARE MANUAL
+ + TMCM-1180
PD86-1180
1-Axis Stepper
Controller / Driver
5.5A RMS/ 24 or 48V DC
USB, RS232, RS485, and CAN
+ +
TMCM-1180 and PD86-1180 Hardware Manual (V1.05 / 2013-JUL-08) 2
www.trinamic.com
Table of Contents
2 Features ........................................................................................................................................................... 3
3 Order Codes ..................................................................................................................................................... 4
4 Mechanical and Electrical Interfacing .............................................................................................................. 5
4.1 TMCM-1180 Dimensions and Mounting Holes ........................................................................................ 5
4.2 PD86-1180 Dimensions and Motor Specifications .................................................................................. 6
4.2.1 Dimensions of PD86-3-1180 ............................................................................................................... 6
4.2.2 Motor Specifications of QSH8618-96-55-700 .................................................................................... 7
4.2.3 Torque Figure of QSH8618-96-55-700 ............................................................................................... 8
4.3 Connectors of TMCM-1180 ...................................................................................................................... 9
4.3.1 Power Connector.............................................................................................................................. 10
4.3.2 Serial Communication Connector .................................................................................................... 12
4.3.3 USB Connector ................................................................................................................................. 12
4.3.4 Output Connector ............................................................................................................................ 13
4.3.5 Input Connector ............................................................................................................................... 14
4.3.6 Step/Direction Connector ................................................................................................................ 16
4.3.7 Encoder Connector ........................................................................................................................... 17
4.3.8 Motor Connector and Specifications ................................................................................................ 18
5 Jumpers .......................................................................................................................................................... 19
5.1 RS485 Bus Termination .......................................................................................................................... 19
5.2 CAN Bus Termination ............................................................................................................................. 19
6 Operational Ratings ....................................................................................................................................... 20
7 Functional Description ................................................................................................................................... 21
7.1 System Architecture .............................................................................................................................. 21
7.1.1 Microcontroller ................................................................................................................................ 21
7.1.2 EEPROM ........................................................................................................................................... 21
7.1.3 Motion Controller ............................................................................................................................ 21
7.1.4 Stepper Motor Driver ....................................................................................................................... 22
7.1.5 sensOstep Encoder ........................................................................................................................... 22
8 TMCM-1180 Operational Description ............................................................................................................ 23
8.1 Calculation: Velocity and Acceleration vs. Microstep and Fullstep Frequency ..................................... 23
9 TMCL .............................................................................................................................................................. 25
10 CANopen ........................................................................................................................................................ 25
11 Life Support Policy ......................................................................................................................................... 26
12 Revision History ............................................................................................................................................. 27
12.1 Document Revision ................................................................................................................................ 27
12.2 Hardware Revision ................................................................................................................................. 27
13 References ..................................................................................................................................................... 27
TMCM-1180 and PD86-1180 Hardware Manual (V1.05 / 2013-JUL-08) 3
www.trinamic.com
2 Features
The PD86-1180 is a full mechatronic solution with state of the arte feature set. It is highly integrated and offers a
convenient handling. The PD86-1180 consists of a NEMA 34 (flange size 86mm) stepper motor, controller/driver
electronics and integrated encoder.
The TMCM-1180 is an intelligent stepper motor controller/driver module featuring the new outstanding coolStep™
technology for sensorless load dependent current control. This allows energy efficient motor operation. With the
advanced stallGuard2™ feature the load of the motor can be detected with high resolution. The module is designed
to be mounted directly on an 86mm flange QMot stepper motor.
MAIN CHARACTERISTICS
Electrical data
- Supply voltage: +24V DC or +48V DC nominal
- Motor current: up to 5.5A RMS (programmable)
PANdrive motor
- Two phase bipolar stepper motor with up to 5.5A RMS nom. coil current
- Holding torque: 7Nm
Encoder
- Integrated sensOstep magnetic encoder (max. 256 increments per rotation) e.g. for step-loss detection under all
operating conditions and positioning
Integrated motion controller
- Motion profile calculation in real-time (TMC428/429 motion controller)
- On the fly alteration of motor parameters (e.g. position, velocity, acceleration)
- High performance microcontroller for overall system control and serial communication protocol handling
Bipolar stepper motor driver
- Up to 256 microsteps per full step
- High-efficient operation, low power dissipation
- Dynamic current control
- Integrated protection
- stallGuard2 feature for stall detection
- coolStep feature for reduced power consumption and heat dissipation
Interfaces
- inputs for stop switches (left and right) and home switch
- general purpose inputs and 2 general purpose outputs
- USB, RS232, RS485 and CAN (2.0B up to 1Mbit/s) communication interfaces
Safety features
- Shutdown input. The driver will be disabled in hardware as long as this pin is left open or shorted to ground
- Separate supply voltage inputs for driver and digital logic – driver supply voltage may be switched off externally
while supply for digital logic and therefore digital logic remains active
Software
- Available with TMCL™ or CANopen
- Standalone TMCL operation or remote controlled operation
- Program memory (non volatile) for up to 2048 TMCL commands
- PC-based application development software TMCL-IDE available for free
- CANopen: CiA 301 + CiA 402 (homing mode, profile position mode and velocity mode) supported
Please see separate TMCL and CANopen Firmware Manuals for additional information
TMCM-1180 and PD86-1180 Hardware Manual (V1.05 / 2013-JUL-08) 4
www.trinamic.com
3 Order Codes
Cables are not included. Add the appropriate cable loom to your order if required.
Order code
Description
Dimensions [mm³]
TMCM-1180 (-option)
TMCM-1180 with coolStep, sensOstep
85.9 x 85.9 x 21.5
PD86-3-1180 (-option)
PD86-3-1180 with coolStep, sensOstep, 7.0 Nm
85.9 x 85.9 x 118.5
Table 3.1 PANdrive or module order codes
Option
Firmware
-TMCL
TMCL firmware
-CANopen
CANopen firmware
Table 3.2 Options for order codes
Component part
Description
TMCM-1180-CABLE
Cable loom for module and PANdrive
Table 3.3 Order codes for component parts
TMCM-1180 and PD86-1180 Hardware Manual (V1.05 / 2013-JUL-08) 5
www.trinamic.com
4 Mechanical and Electrical Interfacing
4.1 TMCM-1180 Dimensions and Mounting Holes
The dimensions of the controller/driver board (TMCM-1180) are approx. 86mm x 86mm in order to fit to the back side
of the 86mm stepper motor. The TMCM-1180 is 21.5mm high without matching connectors. There are four mounting
holes for M4 screws.
85.9
85.9
67.45
72
72
13.9
13.9
2
8
2
8
67.45
4.55
18.45
18.45
4.55
R5.9
81.35
81.35
TMCM-1180
M4
Figure 4.1 Dimensions of TMCM-1180 and mounting holes
TMCM-1180 and PD86-1180 Hardware Manual (V1.05 / 2013-JUL-08) 6
www.trinamic.com
4.2 PD86-1180 Dimensions and Motor Specifications
The PD86-1180 includes the TMCM-1180 stepper motor controller/driver electronic module, a magnetic encoder based
on sensOstep technology and an 86mm flange size bipolar hybrid stepper motor.
4.2.1 Dimensions of PD86-3-1180
96
8.38
73.02±0.05
1.52
22.5 max
1.4
85.85
4.1
17
31.75±1
25
1.1
11.6 12.7
85.9
85.9
69.5±0.2
69.5±0.2
400 min.
4 x ø 5.5
73.02±0.05
12.7
11.6
Figure 4.2 PD86-3-1180 dimensions
TMCM-1180 and PD86-1180 Hardware Manual (V1.05 / 2013-JUL-08) 7
www.trinamic.com
4.2.2 Motor Specifications of QSH8618-96-55-700
Units
QSH8618-96-55-700
V
2.56
A
5.5
Ω
0.45
mH
4.5
Nm
7.0
Nm
gcm2
2700
Kg
2.8
B
Ω
100M
VAC
500
N°
4
V
140
°
1.8
%
5
mm
85.85
mm
96
mm
12.7
mm
31.75
mm
25.0
mm
0.02
mm
0.08
N
220
N
60
°C
-20… +50
°C
max. 80
Table 4.1 Motor specifications of QSH8618-96-55-700
TMCM-1180 and PD86-1180 Hardware Manual (V1.05 / 2013-JUL-08) 8
www.trinamic.com
4.2.3 Torque Figure of QSH8618-96-55-700
The torque figure details the motor torque characteristics for full step operation in order to allow simple comparison.
For full step operation there are always a number of resonance points (with less torque) which are not depicted. These
will be minimized by microstep operation.
Figure 4.3 QSH8618-96-55-700 speed vs. torque characteristics
0
1
2
3
4
5
6
100 1000 10000
Torque [Nm]
Speed [Pps]
Testing conditions: 48V; 5,5A Full step
TMCM-1180 and PD86-1180 Hardware Manual (V1.05 / 2013-JUL-08) 9
www.trinamic.com
4.3 Connectors of TMCM-1180
The controller/driver board of the PD86-1180 offers eight connectors including the motor connector which is used
internally for attaching the motor coils to the electronics. In addition to the power connector there are two connectors
for serial communication (one for mini-USB and one for RS232/RS485/CAN) and two connectors for additional input and
output signals. Further there is one connector for Step/Direction and another for the encoder.
The output connector offers two general purpose outputs, one power supply voltage output, and one hardware
shutdown input. Leaving the shutdown input open or tying it to ground will disable the motor driver stage in hardware.
For operation, this input should be tied to the supply voltage.
The input connector offers two inputs for stop switches (left and right), one home switch input, two general purpose
inputs and one connection to the system or signal ground.
Motor
USB
Power
Serial
communication
Input OutputStep/DirEncoder
1
1
1
1111
Figure 4.4 Overview connectors
Label
Connector type
Mating connector type
Power
JST B4P-VH
JST VH series, 4 pins, 3.96mm pitch
Connector housing JST: VHR-4N
Contacts JST: BVH-21T-P1.1
Motor
JST B4P-VH
JST VH series, 4 pins, 3.96mm pitch
Connector housing JST: VHR-4N
Contacts JST: BVH-21T-P1.1
Mini-USB
Molex 500075-1517
Mini USB Type B vertical receptacle
Any standard mini-USB plug
Serial
communication
CI0108P1VK0-LF
CVIlux CI01 series, 8 pins, 2mm pitch
Connector housing CVIlux: CI01085000-A
Contacts CVIlux: CI01T011PE0-A
or
Connector housing JST: PHR-8
Contacts JST: SPH-002T-P0.5S
Wire: 0.22mm2
TMCM-1180 and PD86-1180 Hardware Manual (V1.05 / 2013-JUL-08) 10
www.trinamic.com
Label
Connector type
Mating connector type
Inputs
CI0106P1VK0-LF
CVIlux CI01 series, 6 pins, 2mm pitch
Connector housing CVIlux: CI01065000-A
Contacts CVIlux: CI01T011PE0-A
or
Connector housing JST: PHR-6
Contacts JST: SPH-002T-P0.5S
Wire: 0.22mm2
Outputs
CI0104P1VK0-LF
CVIlux CI01 series, 4 pins, 2mm pitch
Connector housing CVIlux: CI01045000-A
Contacts CVIlux: CI01T011PE0-A
or
Connector housing JST: PHR-4
Contacts JST: SPH-002T-P0.5S
Wire: 0.22mm2
Encoder
CI0105P1VK0-LF
CVIlux CI01 series, 5 pins, 2mm pitch
Connector housing CVIlux: CI01055000-A
Contacts CVIlux: CI01T011PE0-A
or
Connector housing JST: PHR-5
Contacts JST: SPH-002T-P0.5S
Wire: 0.22mm2
Step/Dir
CI0104P1VK0-LF
CVIlux CI01 series, 4 pins, 2mm pitch
Connector housing CVIlux: CI01045000-A
Contacts CVIlux: CI01T011PE0-A
or
Connector housing JST: PHR-4
Contacts JST: SPH-002T-P0.5S
Wire: 0.22mm2
Table 4.2 Connectors and mating connectors, contacts and applicable wire
4.3.1 Power Connector
This module offers separate power supply inputs for digital logic (pin 2) and driver/power stage (pin 1). Both supply
inputs use common ground connections (pin 3 and 4). This way, power supply for the driver stage may be switched off
while still maintaining position and status information when keeping digital logic supply active.
+UDRIVER SUPPLY ONLY
In case power supply is provided to the power section only, an internal diode will distribute power to the logic section
also. So, when separate power supplies are not required it is possible to just use pin 1 and 4 for powering the module.
14
Pin
Label
Description
1
+UDriver
Module + driver stage power supply input
(nom. +48V DC)
2
+ULogic
(Optional) separate digital logic power supply input
(nom. +48V DC)
3
GND
Module ground (power supply and signal ground)
4
GND
Module ground (power supply and signal ground)
Table 4.3 Connector for power supply
To ensure reliable operation of the unit, the power supply has to have a sufficient output capacitor and the supply cables
should have a low resistance, so that the chopper operation does not lead to an increased power supply ripple directly
at the unit. Power supply ripple due to the chopper operation should be kept at a maximum of a few 100mV.
TMCM-1180 and PD86-1180 Hardware Manual (V1.05 / 2013-JUL-08) 11
www.trinamic.com
HINTS FOR POWER SUPPLY
- keep power supply cables as short as possible
- use large diameters for power supply cables
CAUTION!
Add external power supply capacitors!
It is recommended to connect an electrolytic capacitor of significant size (e.g. 2200 µF / 63 V) to the
power supply lines next to the PD-1160 especially if the distance to the power supply is large (i.e.
more than 2-3m)! In larger systems a zener diode circuitry might be required in order to limit the
maximum voltage when the motor is operated at high velocities.
Rule of thumb for size of electrolytic capacitor: c = 1000 μF
A× IMOT
In addition to power stabilization (buffer) and filtering this added capacitor will also reduce any
voltage spikes which might otherwise occur from a combination of high inductance power supply
wires and the ceramic capacitors. In addition it will limit slew-rate of power supply voltage at the
module. The low ESR of ceramic-only filter capacitors may cause stability problems with some
switching power supplies.
Do not connect or disconnect motor during operation!
Motor cable and motor inductivity might lead to voltage spikes when the motor is disconnected /
connected while energized. These voltage spikes might exceed voltage limits of the driver MOSFETs
and might permanently damage them. Therefore, always disconnect power supply before
connecting / disconnecting the motor.
Keep the power supply voltage below the upper limit of 55V!
Otherwise the driver electronics will seriously be damaged! Especially, when the selected operating
voltage is near the upper limit a regulated power supply is highly recommended. Please see also
chapter Fehler! Verweisquelle konnte nicht gefunden werden.Fehler! Verweisquelle konnte nicht ge
funden werden. (operating values).
There is no reverse polarity protection!
The module will short any reversed supply voltage due to internal diodes of the driver transistors.
TMCM-1180 and PD86-1180 Hardware Manual (V1.05 / 2013-JUL-08) 12
www.trinamic.com
4.3.2 Serial Communication Connector
A 2mm pitch 8 pin connector is used for serial communication. With this connector the module supports RS232, RS485
and CAN communication.
18
Pin
Label
Description
1
RS232_TxD
RS232 transmit data
2
RS232_RxD
RS232 receive data
3
GND
Module ground (system and signal ground)
4
CAN_H
CAN_H bus line (dominant high)
5
CAN_L
CAN_L bus line (dominant low)
6
GND
Module ground (system and signal ground)
7
RS485+
RS485 non-inverted bus signal
8
RS485-
RS485 inverted bus signal
Table 3.3 Connector for serial communication
4.3.3 USB Connector
A 5-pin mini-USB connector is available on board (might depend on assembly option).
15
Pin
Label
Description
1
VBUS
+5V power
2
D-
Data –
3
D+
Data +
4
ID
Not connected
5
GND
ground
Table 3.4 Mini USB connector
TMCM-1180 and PD86-1180 Hardware Manual (V1.05 / 2013-JUL-08) 13
www.trinamic.com
4.3.4 Output Connector
A 2mm pitch 4 pin connector is used for connecting the two general purpose outputs and the driver stage hardware
shutdown input pin to the unit.
In order to enable the motor driver stage connect /Shutdown (pin 2) to +ULogic (pin 1)!
4
1
Pin
Label
Description
1
+ULogic
Module digital logic power supply – connected to pin 2
of power supply connector
2
/Shutdown
/Shutdown input – has to be connected to power supply
(e.g. pin 1 of this connector) in order to enable driver.
Connecting this input to ground or leaving it
unconnected will disable driver stage
3
OUT_0
Open collector output with integrated freewheeling
diode, +24V compatible
4
OUT_1
Open collector output with integrated freewheeling
diode, +24V compatible
Table 4.4 Output / /Shutdown connector
GPO
freewheeling
diode
integrated
on-board
GPO
GPO
galvanic isolation
opto-coupler
supply voltage
e.g. +24V
supply voltage
e.g. +24V
supply voltage
e.g. +24V
Figure 4.5 Possible circuits for GPO
GND
1k00
GND
OUT_0
1k00
OUT_1
+ULogic
+ULogic
OUT_0
OUT_1
Figure 4.6 Internal circuit of the outputs
TMCM-1180 and PD86-1180 Hardware Manual (V1.05 / 2013-JUL-08) 14
www.trinamic.com
4.3.5 Input Connector
A 2mm pitch 6 pin connector is used for connecting general purpose inputs, home and stop switches to the unit.
Mating connector housing: PHR-6
Mating connector contacts: SPH-002T-P0.5S
16
Pin
Label
Description
1
IN_0
General purpose input, +24V compatible
2
IN_1
General purpose input, +24V compatible
3
STOP_L
Left stop switch input, +24V compatible, programmable
internal pull-up (1k to +5V)
4
STOP_R
Right stop switch input, +24V compatible,
programmable internal pull-up (1k to +5V)
5
HOME
Home switch input, +24V compatible, programmable
internal pull-up (1k to +5V)
6
GND
Module ground (system and signal ground)
Table 4.5 Input / Stop / Home switch connector
+24V
GPI
Figure 4.7 Possible circuit for GPI
IN_0/1
22kO10kO
GND
+3.3V
GND
IN_0/1
100nF
GND
Figure 4.8 Internal circuit of the inputs
TMCM-1180 and PD86-1180 Hardware Manual (V1.05 / 2013-JUL-08) 15
www.trinamic.com
4.3.5.1 Left and Right Limit Switches
The TMCM-1180 can be configured so that a motor has a left and a right limit switch (Figure 4.9).
The motor stops when the traveler has reached one of the limit switches.
left stop
switch
right stop
switch
REF_L_x REF_R_x
motor
traveler
Figure 4.9 Left and right limit switches
4.3.5.2 Triple Switch Configuration
It is possible to program a tolerance range around the reference switch position. This is useful for a triple switch
configuration, as outlined in Figure 4.10. In that configuration two switches are used as automatic stop switches, and
one additional switch is used as the reference switch between the left stop switch and the right stop switch. The left
stop switch and the reference switch are wired together. The center switch (travel switch) allows for a monitoring of
the axis in order to detect a step loss.
left stop
switch
motor
traveler
REF_L_x
right stop
switch
REF_R_x
reference
switch
Figure 4.10 Limit switch and reference switch
4.3.5.3 One Limit Switch for Circular Systems
If a circular system is used (Figure 4.11), only one reference switch is necessary, because there are no end-points in such
a system.
motor
ref switch
REF_L_x
eccentric
Figure 4.11 One reference switch
TMCM-1180 and PD86-1180 Hardware Manual (V1.05 / 2013-JUL-08) 16
www.trinamic.com
4.3.6 Step/Direction Connector
A 2mm pitch 4 pin connector is used for connecting the Step/Dir interface.
4
1
Pin
Label
Description
1
OC_COM
Common supply / opto-coupler (+5V .. +24V)
2
OC_EN
Enable signal
3
OC_STEP
Step signal
4
OC_DIR
Direction signal
Table 4.6 Step/Dir connector
C
E
A
K
EN
DIR
STEP
OC_COM
OC_EN
OC_DIR
OC_STEP
GND
+3.3V
4k754k75
4k75
GND
Iconst = 8mA
Iconst = 8mA
Figure 4.12 Internal circuit of the Step/Dir interface
TMCM-1180 and PD86-1180 Hardware Manual (V1.05 / 2013-JUL-08) 17
www.trinamic.com
4.3.7 Encoder Connector
A 2mm pitch 5 pin connector is used for connecting the Encoder.
Mating connector housing: PHR-5
Mating connector contacts: SPH-002T-P0.5S
1 5
Pin
Label
Description
1
ENC_A
Encoder A-channel
2
ENC_B
Encoder B-channel
3
ENC_N
Encoder N-channel
4
GND
Power and signal ground
5
+5V_output
+5V output for encoder power supply (max. 100mA)
Table 4.7 Encoder connector
100pF
GND GND
2k2
2k2
2k2
0.1A
2k2
2k2
2k2
+5V +5V +5V +5V
GND GND GND
1
1
1
1
1
ENC_A
ENC_B
ENC_N
Figure 4.13 Internal circuit of encoder interface
TMCM-1180 and PD86-1180 Hardware Manual (V1.05 / 2013-JUL-08) 18
www.trinamic.com
4.3.8 Motor Connector and Specifications
A 3.96mm pitch 4 pin connector is used for motor connection. Both motor coil windings (bipolar stepper motor) are
connected to this connector.
Mating connector housing: VHR-4N
Mating connector contacts: BVH-21T-P1.1
14
Pin
Label
Description
1
OA1
Motor coil A
2
OA2
Motor coil A
3
OB1
Motor coil B
4
OB2
Motor coil B
Table 4.8 Connector for motor
TMCM-1180 and PD86-1180 Hardware Manual (V1.05 / 2013-JUL-08) 19
www.trinamic.com
5 Jumpers
Most settings of the board are done through the software. Nevertheless, a few jumpers are available for configuration.
CAN bus
termination
RS485 bus
termination
Figure 5.1 RS485 and CAN bus termination
5.1 RS485 Bus Termination
The board includes a 120 Ohm resistor for proper bus termination of the RS485 interface. When this jumper is closed,
the resistor will be placed between the two differential bus lines RS485+ and RS485-.
5.2 CAN Bus Termination
The board includes a 120 Ohm resistor for proper bus termination of the CAN interface. When this jumper is closed, the
resistor will be placed between the two differential bus lines CAN_H and CAN_L.
TMCM-1180 and PD86-1180 Hardware Manual (V1.05 / 2013-JUL-08) 20
www.trinamic.com
6 Operational Ratings
The operational ratings shown below should be used as design values. In no case should the maximum values been
exceeded during operation.
Symbol
Parameter
Min
Typ
Max
Unit
+UDriver / +ULogic
Power supply voltage for operation
18
24 or 48
55
V DC
ICOIL_peak
Motor coil current for sine wave peak
(chopper regulated, adjustable via
software)
0
7.8
A
ICOIL_RMS
Continuous motor current (RMS)
0
5.5
A
ISUPPLY
Power supply current
<< ICOIL
1.4 * ICOIL
A
TENV
Environment temperature at rated
current (no forced cooling required)
-20
+50*)
°C
Table 6.1 General operational ratings of the module
*) The controller driver electronics has been tested inside a climate chamber running at full current (5.5A RMS) for
30min without air convection at 50°C environmental temperature.
The motor might heat up well above 50°C when running at full current without proper cooling. This might substantially
increase the environmental temperature for the electronics. When using the coolStep operation mode, the actual
current might be substantially less than programmed max. current producing and temperature.
Page is loading ...
Page is loading ...
Page is loading ...
Page is loading ...
Page is loading ...
Page is loading ...
Page is loading ...
  • Page 1 1
  • Page 2 2
  • Page 3 3
  • Page 4 4
  • Page 5 5
  • Page 6 6
  • Page 7 7
  • Page 8 8
  • Page 9 9
  • Page 10 10
  • Page 11 11
  • Page 12 12
  • Page 13 13
  • Page 14 14
  • Page 15 15
  • Page 16 16
  • Page 17 17
  • Page 18 18
  • Page 19 19
  • Page 20 20
  • Page 21 21
  • Page 22 22
  • Page 23 23
  • Page 24 24
  • Page 25 25
  • Page 26 26
  • Page 27 27

Trinamic TMCM-1180-CANopen Owner's manual

Trinamic
Brand
Trinamic
Model
TMCM-1180-CANopen
Type
Owner's manual
This manual is also suitable for
Download PDF
report

Ask a question and I''ll find the answer in the document

Finding information in a document is now easier with AI

Related papers

Other documents